Director of National Intelligence Dennis Blair told a Congressional committee on Wednesday that the military has the authority to target US citizens in other countries if it believes that they 'have been radicalized' and are 'involved with a group that is trying to harm the US.'

The term he used for the permission to kill was 'direct action.'  Others call it 'assassination.'

Also, from the Washington Times:

Mr. Blair also said in his testimony that the charter for a special unit to interrogate terrorists known as the High-Value Detainee Interrogation Group, or HIG, was signed last week and that the HIG was now fully operational.  Last month, Mr. Blair, appearing before the Senate homeland security committee, criticized the Obama administration's handling of Mr. Abdulmutallab and the fact that he was read his constitutional rights instead of being sent to the HIG. He later issued a statement acknowledging that the HIG at the time was not yet operational.

Just after 9/11, George W. Bush signed a classified 'intelligence finding' that permits the assassination of 'suspected terrorists.'  Blair announced that the Obama administration is continuing the process, and that the CIA and Pentagon officials can launch strikes on suspected terrorists without permission of higher-ups.

In the case of Americans suspected of terrorism, they must seek permission before launching the strikes.  It is unclear whether this requires Presidential permission, or as former CIA operatives say off the record, the permission of a secret committee of Intel people plus a member of the White House staff.

It brings up some troubling questions.  First, is a person a terrorist because someone believes they are, and second, is this an end run around the US Constitution?

The extension of war into Yemen seems to be prompting this.  In 2002 US forces did kill one US citizen, Kemal Derwish, in a missile attack targeting a Yemeni terrorist. 

On Christmas eve, US forces attempted to kill Anwar Al-Awlkai, a 'US-born  radical cleric who allegedly advised the suspected Fort Hood shooter and the alleged Christmas Day bomber.'  (Al-Awaki apparently escaped the missile strike.)

JSOC incursions into Yemen have increased, and to a lesser degree into Somalia.  JSOC apparently act as 'advisors.'  There is a short list of targets that include several Americans.

 Constitutional Law Scholar Jonathan Turley has this to say:

 As reaffirmed in cases like Reid v. Covert, 354 U.S. 1 (1957), American citizens have the same protections regardless of whether they are without or outside of the country. In that case, two American women who murdered their husbands on American military bases abroad were given the same protections under the Fifth Amendment regardless of the fact that they were located and committed the crimes abroad.

If a president can kill U.S. citizens abroad, why not within the United States? What is the limiting principle beyond the practicalities?

Glenn Greenwald weighs in with this column:  Lynch Mob Mentality

If I had the power to have one statement of fact be universally recognized in our political discussions, it would be this one:

The fact that the Government labels Person X a "Terrorist" is not proof that Person X is, in fact, a Terrorist.

That proposition should be intrinsically understood by any American who completed sixth grade civics and was thus taught that a central prong of our political system is that government officials often abuse their power and/or err and therefore must prove accusations to be true (with tested evidence) before they're assumed to be true and the person punished accordingly.  In particular, the fact that the U.S. Government, over and over, has falsely accused numerous people of being Terrorists -- only for it to turn out that they did nothing wrong -- by itself should compel a recognition of this truth.  But it doesn't.  

 Roger Cressey, a former National Security Council official, takes a different view, saying:

 If you are stupid enough to be associated with known Al Qaeda operatives in a known Al Qaeda safe haven, you're putting your life at risk.

 Paul Gimigliano, a CIA spokesman, says:

The agency's counterterrorism operations are lawful, aggressive, precise, and effective. White House and Pentagon spokesmen did not respond to requests for comment.